Details

Big cities call for big protection, and Kryptonite's New York Chain delivers with 12mm six-sided chain links made from hardened manganese steel. Wrap this burly lock around your frame worry-free thanks to the durable nylon cover that protects your bike's paint from scratches. Leave with peace of mind knowing the 14mm hardened Max-Performance steel shackle mated to the Evolution Series 4 Disc Lock is on duty. With a double deadbolt design to protect against twist attacks, would-be thieves don't stand a chance. It comes with three stainless steel keys--one of which is lighted for night access!

Kryptonite's Key Safe Program is an easy way to ensure you always have access to your lock's capabilities. Simply register your key number with Kryptonite and if you lose your keys, your first set of replacement keys are free!

Incredibly strong lock.
Pros:
Opens easily and the length of the chain gives you some options when it comes to locking up to unorthodox objects (trees, columns, etc). Lighted key is cool.
Cons:
very, VERY heavy. nearly 10 pounds. not a lot of carrying options, but I have figured out a way to wrap it around the headset/top tube of my single speed in a way that doesn't mess with steering. Too heavy to wear around neck or waist, you can put it in a bag if you are carrying one. A bit pricey, but you get what you pay for.